Air-brake.



No. 665,34I. Patented Ian. I, IBM. .J. E. NOBMAND.

AIR BRAKE.

(Application filed Mar. 5, 1900.)

(No Model.) 2 Sheets-Sheat l.

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W. a W ATTORNEY THE Noam PETERS c0. Pnumumc. WAHINGTmL u. c.

. Patented Jan. I, I90l. J. E. NORMAND.

No. 665,34l.

AIR BBAK E.

(Application filed Mar. 5, 1900.)

2 Sheets-Sheet 2.

(No Model.)

WITNESSES:

ATTORNEY THE Noams wzrzns w. PHOYO-LITHQ, msnmomu. n. c.

UNITED STATES PATENT OFFICE.

JOSEPH E. NORMAND, OF WATERTOWN, NEW YORK.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 665,341, dated January 1, 1901. Application filed March 5, 1900. Serial No. 7,336. (No model.)

T0 all whom, it may concern.-

Be it known that I, JOSEPH E. NORMAND, a citizen of the United States of America, and a resident of Watertown, county of Jefferson, and State of New York, have invented certain new and useful Improvements in Air- Brakes, of which the following is a specification.

My invention relates to improvements in apparatus for storing air under pressure, and my invention relates more particularly to duplicate check-valves for a system of storagereservoirs.

My improvement is particularly applicable to air-brake systems, and I contemplate the employment therein of a primary reservoir, one or more storage-reservoirs, and means whereby a predetermined amount of pressure may be attained in the primary reservoir before any pressure is produced in the storagereservoirs, and whereby such pressure may be maintained in the primary reservoir regardless of the fact that the pressure in the storage-reservoirs may be below that of the primary reservoir, and whereby the fluid under pressure in the storage-reservoirs may be withdrawn through the primary reservoir should the pressure in the primary reservoir fall below that of the storage-reservoirs.

My invention further consists in certain novel details of construction and combination of parts, as will be hereinafter more fully described. I

The objects of my invention are to provide, primarily; for the storage of a small quantity of fluid and the compression of the same to a predetermined pressure, to make provision for the storage of a larger quantity of fluid than shall be primarily compressed for the attainment of such predetermined pressure, to provide that upon the withdrawal of fluid under pressure the pressure of the primary supply shall never fall below that of any other portion of the supply, and that the reattainment of the pressure of the primary supply shall be accomplished before the recharging of the larger storage-supply.

I will now proceed to describe my invention in detail, with reference to the accompanying drawings, and will then point out the novel features in the claims.

In the drawings, Figure 1 is a diagrammatic view of a storage system embodying my invention. Fig. 2 is a central vertical section of a duplex check-valve employed. Fig. 3 is a horizontal transverse section taken on the plane of the line 3 3 of Fig. 2.

Similar reference characters designate corresponding parts in the several figures.

In carrying out my invention I employ a primary reservoir,(designated in the drawings by the reference character 4:.) Fluid under pressure is supplied to the primary reservoir 4, as through a pipe 5. A suitable checkvalve 6 is ordinarily employed, and the fluid under pressure from the reservoir at may be led away and used as desired through a pipe 7. So far the description and arrangement of parts are old and Well known, and further detailed description or illustration is unnecessary.

It is desirable in certain systems for using air under pressuresuch, for instance, as in air-brake systems on street-carsthat the primary reservoir shall be as small as possible in order that a sufficient pressure may be attained therein in as short a space of time as possible. At the same time it is very desirable that a comparatively large quantity of compressed fluid shall be stored in order that the pressure shall not materially decrease upon such quantity being taken therefrom as shall be necessary for use from time to time. To provide an apparatus for accomplishing such purpose, I employ one or more storage-reservoirs in addition to the primary reservoir 4. I have shown in the drawings one of such storage-reservoirs, but it is understood that I may use as many as may be desired.

The primary reservoir 4 and the storagereservoir designated by the reference character 8 are in communication with each other through a pipe 9. A duplex check-valve 10 is arranged in the pipe 9 and the relative pressures in the primary and storage reservoirs are arranged and controlled by the said duplex check-valve.

I will now proceed to describe the duplex check-valve in detail, and for this purpose refer more particularly to Figs. 2 and 3. 11 designates a suitable casing, the interior of which is divided into two chambers 12 and 13. The chamber 12 is arranged to connect directly with the primary reservoir 4 and the chamber 13 with the storage-reservoir 8. In the diaphragm 14:, which divides the two chambers 12 and 13, are arranged two valve-seats 15 and 16. Fitted to the valve-seat 15 is a check-valve 17. A light spring 18 tends to close the valve, but is so arranged that the valve shall be free at all times to open and permit the flow of fluid from the chamber 13 to the chamber 12. The said valve will, however, operate to prevent the flow of fluid in the contrary directionthat is to say, from the chamber 12 to the chamber 13. The said valve is suitably mounted and arranged to slide in an extension 19 of the casing 11, which extension is closed by means of a cap 20. The valve-seat 16 is provided with a valve 21, secured to a hollow stem 22, which is mounted in a head 23, secured to the easing 11. The outer end of the head 23 is closed by a screw-threaded plug 24. A pressure-spring 25 is arranged between the plug 24 and the valve 21 and tends to force the said valve down to its seat. The pressure exerted by the spring 25 may be regulated as desired by the adjustment of the screwthreaded plug 24. The valve 21 opens in the same direction as does the valve 1'7that is to say, from the chamber 13 toward the chamber 12. The valve 21is, however, opened by pressure-actuated means operated from within the chamber 12 and when so open permits fluid to pass from the said chamber 12 to the chamber 13'. Such pressure-actuated means is here shown as provided by so constructing the valve-plug 22 as to form a piston and which, presenting one face toward the chamber 12, will receive the pressure therefrom toward the said face. The tendency of the pressure in the chamber 12 will be, therefore, to move the piston-plug outwardly and so lift the valve. Such tendency will be resisted by the spring 25, and hence the said valve will not be lifted until such resistance has been overcome. For example, I may set the spring so that it will resist a pressure of forty pounds to the square inchin the chamber 12, in which case fluid under pressure will not pass the said valve until the pressure in the chamber 12, and hence in the reservoir 4, will have risen above forty pounds to the square inch. When this shall have happened, the valve 21 will be lifted and the fluid will be discharged into the chamber 13 and from thence into the storage-reservoir 8. Upon the continued inflow of fluid under pressure the reservoir 8 will gradually be filled, as will anyother reservoirs that may be in connection therewith.

If after the filling of the reservoir 4 and during the filling of the reservoir 8 the fluid under pressure shall be withdrawn from the reservoir 4 for such purpose, as in an airbrake system for applying the brakes, and the pressure in the primary reservoir shall consequently fall below forty pounds to the square inch, the valve 21 will immediately be closed by action of the spring 25 and the fluid under pressure will cease to flow into the reservoir 8 until bya continued supply of the fluid through the pipe 5 the pressure in the reservoir 4 shall again have reached forty pounds to the square inch. By reason of the continued supply of fluid the storage-reservoir 8 will finally be filled until both the primary and storage reservoirs are at a uniform pressure of forty pounds to the square inch. Itis understood,ofcourse,that suitable means may be employed for cutting off the supply of fluid when a maximum pressure shall have been attained in all the reservoirs. Now when fluid is withdrawn from the primary reservoir Land the pressure therein shall consequently be lowered, fluid from the storagereservoir 8 will immediately be discharged past the check-valve 17 and will practically take the place of the fluid thus withdrawn. In recharging, the fluid in the primary reservoir will first be raised to its maximum pressure and in the manner just described, and the storage-reservoir will then be recharged from the overflow therefrom.

By the foregoing it will be seen that I. obtain the benefits of a small reservoir wherein a suitable head of pressure can be quickly attained, together with the benefits derived from the use of larger storage capacity, in which, upon the withdrawal of fluid for use, the head of pressure is very gradually lowered.

In order to obtain a better freedom of movement of the valve 22 and at the same time to avoid leakage past the piston 22, I have provided a diaphragm 26. Such diaphragm permits a sufficient movement of the valve 21, saves the friction and expense of packingrings, and absolutely prevents the escape of fluid-pressure past the moving parts.

In case it is desired to employ more than one additional storage-reservoir the said reservoirs may be connected together freely or each successive storage-reservoir may have a duplex check-valve arranged between it and the reservoir preceding it.

I wish it to be clearly understood that I do not intend to limit myself to the exact details and construction of parts as herein described and illustrated, as the same may obviously be departed from within wide limits without departing from the spirit and scope of my invention.

What I claim is 1. A duplex check-valve comprising a casing having two valve-seats, a check-valve fitted to one seat and adapted to open freely in one direction, a valve fitted to the other seat and adapted to be opened by fluid-pressure exerted in the opposite direction to that of the fluid operating to open the check-valve, a spring operating to close the said last-named valve, and a regulating-screw for regulating the tension of said spring.

2. A duplex check-valve comprising a casing having two valve-seats, a check-valve fitted to one seat and adapted to open freely in one direction, a valve fitted to the other seat, a spring operating to close said valve, and pressure-actuated means for opening the said valve against the resistance of said spring.

3. A duplex check-valve comprising a casing having two valve-seats, a check-valve fitted to one seat and adapted to open freely in one direction, a valve fitted to the other seat and arranged to open in the same direction relatively to the passage of the fluid, a spring operating to close the said valve, and pressure-actuated means for opening the said valve against the resistance of said spring.

4. A duplex check-valve comprising a casing having two valve-seats, a check-valve fitted to one seat and adapted to open freely in JOSEPH E. NORMAND.

Witnesses:

JNo. S. PORTER, G. F. CARRINGTON. 

